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A224725 Number of (n+3) X 8 0..2 matrices with each 4 X 4 subblock idempotent. 1

%I

%S 4257,3123,3775,4209,4498,5727,7575,9778,12188,15746,21068,28510,

%T 38276,51515,69988,95816,131320,179974,247009,339781,467963,644706,

%U 888388,1224747,1689190,2330279,3214950,4435881,6121153,8447413,11658240

%N Number of (n+3) X 8 0..2 matrices with each 4 X 4 subblock idempotent.

%H R. H. Hardin, <a href="/A224725/b224725.txt">Table of n, a(n) for n = 1..159</a>

%F Empirical: a(n) = 3*a(n-1) - 2*a(n-2) - 2*a(n-3) + 4*a(n-4) - 3*a(n-5) + 2*a(n-7) - a(n-8) for n>10.

%F Empirical g.f.: x*(4257 - 9648*x + 2920*x^2 + 7644*x^3 - 11361*x^4 + 8480*x^5 + 2077*x^6 - 6522*x^7 + 2104*x^8 + 47*x^9) / ((1 - x)^3*(1 + x)*(1 - x - x^4)). - _Colin Barker_, Sep 04 2018

%e Some solutions for n=2:

%e ..1..0..0..0..0..0..0..0....1..0..0..0..0..2..0..0....1..1..1..1..1..0..1..1

%e ..1..0..0..0..0..0..0..2....1..0..0..0..0..1..0..0....0..0..0..0..0..0..0..0

%e ..1..0..0..0..0..0..0..0....2..0..0..0..0..1..0..0....0..0..0..0..0..0..0..0

%e ..2..0..0..0..0..0..0..1....1..0..0..0..0..1..0..0....0..0..0..0..0..0..0..0

%e ..0..0..0..0..0..0..0..1....1..0..0..0..0..1..0..0....1..2..1..1..1..1..1..1

%Y Column 5 of A224728.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 16 2013

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Last modified January 28 18:24 EST 2022. Contains 350657 sequences. (Running on oeis4.)